Showing papers in "Engineering Geology in 1999"

TL;DR: In this article, a simple formalism is presented to model the behavior of expansive clays, where two levels of structure are considered, one for wetting and the other for drying, and a mathematical formulation of the model is described and its performance finally assessed by comparison with laboratory tests.

TL;DR: In this paper, three classes of experiments are considered to provide information for two artificially prepared Boom clay fabrics: mercury intrusion/extrusion tests, main wetting/drying paths; and water inflow/outflow transient (permeability) tests.

TL;DR: In this paper, the authors applied correlation analysis to investigate the relationships between petrographical and engineering properties of granitic rocks, and found that the influence of the textural characteristics on the engineering properties appears to be more important than the mineralogy.

TL;DR: In this paper, a structural model consisting of serial and parallel parts with three phase-components, solid, liquid and gas, is developed to give information on soil structures, where the structure model is characterized by the ratio of the serial parts, which have different electrical conductivities at given directions.

TL;DR: In this article, controlled flow-rate gas injection experiments have been performed on precompacted samples of KBS-3 specification Mx80 1 buffer bentonite using helium as a safe replacement for hydrogen.

TL;DR: In this article, a detailed description of the so-called composite model for transient and steady state creep is given, which is based on micromechanisms and is able to model deformation in a wide range of stresses and temperatures, but also after stress decrease.

TL;DR: In this paper, the failure modes of slide-debris flows may be classified into translational slides and rotational slides, and the former are predominant, while the latter may destroy cohesion along the failure surface and locally within the interior.

TL;DR: In the reconnaissance gallery of the Mont Terri motorway tunnel, in north-western Switzerland, in a Mesozoic shale formation, the Opalinus Clay (Aalenian), an international research project is under the patronage of the Swiss National Hydrological and Geological Survey as discussed by the authors.

TL;DR: In this paper, an image analysis technique is suggested to estimate the porosity of the vesicular basalt, and the estimated values were correlated against the calculated porosity values using core samples, and were found to have excellent correlation (R=0.99).

TL;DR: The use of ground granulated blastfurnace slag (GGBS), an industrial byproduct, is well established as a binder in many cement applications where it provides enhanced durability and high resistance to sulphate attack.

TL;DR: In this paper, the energy status of the soil-water (i.e., pore-water) provides the focus for the mechanistic view of the microstructure and mesostructure interactions that govern the development of those "matric" and "osmotic" forces responsible for water uptake by the swelling soils.

TL;DR: This paper examined conditions for failure in compression by crack propagation and coalescence, and for failure by sloughing in which pore water pressure produces a net tension perpendicular to the wall of the void.

TL;DR: In this paper, the potential of marble dust as a stabilizing additive to red tropical soils was evaluated and the results showed that the geotechnical parameters of red tropical soil are improved substantially by the addition of marble sand; plasticity was reduced by 20 to 33% and strength and California bearing ratio increased by 30 to 46% and 27 to 55% respectively.

TL;DR: In this article, the swelling shrinkage properties of the compacted expansive soil in Huaiyin Section of the Ning-Lian Highway are introduced, and swelling-shrinkage mechanisms are discussed based on changes in soil water content, dry density, material composition and fabric.

TL;DR: In this article, the authors used a flexible wall permeameter to measure water transport by chemical osmosis in a commercially available Wyoming Na-bentonite and obtained a reflection coefficient of 0.3 and 0.01, which is significantly lower than those predicted by the Fritz-Marine model.

TL;DR: Reliability and probability theories are developed in this paper for assessing the reliability index and the corresponding probability of failure of multi-layered embankment dams and slopes.

TL;DR: In this article, the most important rock type in the Natal Group is the Newspaper Member from which sample material was obtained, which is a fine to medium grained arkosic sandstone.

TL;DR: In this paper, a very high probability of the existence of a deep underground biosphere in granitic rock aquifers in Sweden is shown. But it is not yet conclusively proven that these organisms are in situ viable and growing, rather than just transported from neutral groundwater.

TL;DR: In this article, the porewater chemistry in compacted bentonite was studied in solution-bentonite interaction experiments, where the parameters varied in the experiments were the bentonite density, bentonite to water ratio (B/W), ionic strength of the solution, and the composition of bentonite.

TL;DR: In this paper, the relationship between landslides and rainfall was investigated using a hydrological and statistical model based on long-term series of daily rainfall data, which was used to determine the return period of cumulative daily rainfall over 1-180 days.

TL;DR: In this article, a unified method of molecular dynamics and homogenization analysis is proposed for predicting the long term behavior of bentonite. But this method is not suitable for high-level radioactive waste disposal.

TL;DR: The factors controlling the expansive nature of the soils and rocks in Northern Oman were studied in this article, where basic geotechnical data from over 40 sites were collected and using empirical relationships, swelling potentials were identified.

TL;DR: In this paper, the diffusion of Na+, Cs+, Co2+ and Sr2+ in bentonite compacted to a dry density of 1800 kg m(-3) and saturated with groundwaters and aqueous solutions of differing ionic strength have been studied.

TL;DR: In this article, the apparent diffusion coefficients of Cs+ ions were determined as functions of the diffusion temperature and the ionic equivalent fraction of Ca2+ ions, and the activation energies for diffusion were also determined from the temperature dependence of the expected diffusion coefficients at each ionic equivalence fraction.

TL;DR: The rapid underground dissolution of gypsum and the evolution of the Gypsum karst in Lithuania and England, results in subsidence problems which can make construction difficult as mentioned in this paper.

TL;DR: In this paper, the influence of clay microstructure and internal energy components on transport prediction in partly saturated swelling soils is discussed, and the need to recognize compatibility between conceptual and numerical models is recognized.

TL;DR: In this article, a series of electrokinetic decontamination experiments including variable conditions such as operating duration, electrical current, concentration of lead and applications of three different chemicals were performed to demonstrate the efficiency of lead removal from natural marine clay sampled in Korea.

TL;DR: In this paper, an apparatus that can be fitted into the chamber of a medical CT was built to conduct geotechnical tests on bentonite, kaolinite, sand, silicon powders, and glass beads.

TL;DR: In this paper, a triaxial test consisting of isotropically consolidated drained (ICD) and undrained compression (ICU) tests and anisotropically consolidated constant deviatoric stress path (CQD) tests was carried out with the aim of investigating the stress-strain behaviour of loosely compacted volcanic-derived soils.

TL;DR: The authors discusses the potential problems posed to European waste isolation sites during erosion by ice and over-pressurizing of meltwater and gasses in a lithosphere flexed by major ice sheets.